Carbureter.



A. 1. CUVIMING.

CARBURETER.

APPLICATION FILED OCT. 18. 1915.

Patented Jan. 23, 1917.

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ALBERT 3'. CUMMING, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR 0F FIFTY-ONE ONE- HUNDREDTHS TO WILLIAM G. JORDAN, OF MINNEAPOLIS, MINNESOTA.

Specification of Letters Patent. Patented Jam., 23, 1191i?,

Application led October 18, 1915. Serial No. 56,443.

To all 'whom t may concern.'

Be it known that I, ALBERT J. CUMMING, a subject of the King of Great Britain, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful ,Improvements in Carbureters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the lart'to which it appertains to'make and use the same.

My invention has for its object to provide an extremely simple and highly ecient carbureter primarily for internal combustion engines; and to such ends, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and delined in the claims.

A Venturi tube, as is well known, is one which has a contraction at some point so that the air or other fluid passes at relatively high velocity at the contracted portion, and such tubes are extensively used in carbureters, but it is customary to provide in the same, yieldingly seated valves which open variably under varying suction, and hence, vary the conducting capacity of the'tube substantiallyproportionate to the force of the suction or partial vacuum created in the tube.

My invention involves a radical departure from the above just noted customary arrangement and consists in providing in the Venturi tube of the carbureter ixed bailles or obstructions located between the air intake end of the tube and the point where the volatile hydrocarbon or fluid fuel is drawn into the said tube.

'llhis improved carbureter is not only well adapted for use in carbureting air with highly volatile fluids, such as gasolene and alcohol, but is capable of use for vaporizing a heav1er volatile liquid, such as kerosene, for example.

In the accompanying drawings which illustrate the invention, like` characters indi-A cate like parts throughout the several views. Referrlng to the drawings: Figure 1 is a vertical sectiomtaken centrally through the `improved carbureter, some parts being shown in full; Fig. 2 is'a transverse section takenon the line m2 m2 of Fig. 1; some parts being shown in full; and Fig. 3 is a detail in l section on the line w8 yme' ofeFig. 2.

The tcrtuous air intake conduit 1 of the carbureter constitutes a Venturi tube and is formed in a casing 2 -that preferably is provided at its central portion with a depending tubular stem 3. y In the intake end of the conduit 1, is a choke valve 4 shown as of the butteriiy type. This choke valve is of the customary construction and may be operated in the usual or any suitable way, but normally, would be held open by a spring, or otherwise, and would have a suitable connection extending to within reach of the operator, such being the customary construction. In the delivery end of the conduit 2, to-wit, in the end which is connected to the explosion chamber, through an intake manifold, or otherwise, is a throttle valve 5, preferably also of the butterfly type. K This l throttle valve is also preferably of well .tubular stem 3. A needle valve 9 is adapted to open and close the upper extremity of the passage through the tubular stem 3, and this needle valve has a threaded portion 10 that engages the threaded seat in the top of the casing 2 and has a smooth portion that works with close engagement through the bushing 8. At its extreme upper end, the needle valve 9 is provided with a suitable hand piece in the form of a knurled head 11. Here it should be noted that the bottom of the casing 2 and the lower intermediate ortion of the conduit 1, immediately surrounding the axial passage ofthe tubular stem 3, are depressed to form a small bowl-like cavity 12. J ust inward of the choke valve 4, the casing 2 is provided with a raised .bame flange 13, and farther inward, the top of the said casing 2 is provided with .a depending bame flange 14. rllhese bame Hanges `l13 and 14 cause the air` drawn in through the so that the air drawn in uw rapidly through, or over the bowl 12, and produces a suction which serves to draw the fluid fuel through the tubular stem 3, as will hereinafter more fully appear.

The numeral 15 indicates a cup for holding the fluid fuel. rlhis cup is preferably of spun or pressed metal, which surrounds the stem 3, and is tightly seated against the lower end thereof, with its upper edge tightly seated against an annular jointed surface 16 formed on a horizontally extended flange 17 of the casing 2. Preferably, the cup 15 is thus secured to the stem'3 by the casing of a drain cock 18 which has a reduced threaded portion that is screwed into internally threaded seat of the said stem 3 in such manner that it forms a continuation of the conduit through the said stem 3. A shouldered portion of the casing 18 tightly clamps the bottom of the cup 15 against the lower end of the stem 3, thereby forming a liquid-tight joint therewith. The passage in the drain tube 18 is normally closed by a valve 19. At points just above the threaded upper end of the tube 18, the tubular stem 3 is provided with intake ports 20 which are always below the level of the fluid fuel y that is contained within the cup 15.

Within the cup 15 and loosely surrounding the stem 3 is an annular float 22 preferably of cork coated with shellac. rlhis float 22,

at one side, is hinged at 23 to the flange 17 of the casing 2.

The fluid fuel is supplied to the carbureter from a suitable source, through a pipe 24, as shown, which is screwed into a sleeve-like projection 25 of the casing. 2. The cavity in this projection 25 is connected to the fuel cup, through a port 26 and a depending valve seat 27 formed in said casing. ln. the said valve seat 27 is a gravity retracted fuel supply valve 28, the upper end of which is conical and is adapted to close the port 26 when forced upward. As shown, the body of this valve 28 is rectangular, so that clearance is a'orded between the same and the seatA 27 for the passage of the fluid fuel. The reduced lower end of said valve 28 rests upon the float 22.' When the fluid fuel reaches a certain altitude, the float 22 will cause the valve 28 to close the intake port 26 and cut off further supply of the fuel to the cup 15; and when the altitude of the fluid fuel has been reduced slightly, the Hoat drops and causes the valveto open the said port 26 and permit a furtherl supply of the fuel to the said cup. In this way, the altitude of the luid fuel in the cup 25 is automatically maintained.

When the engine is in operation, the air dfawn through the conduit 1 will draw up the volatile fluid fuel through the tubular stem 3 and thereby carburet the air. rllhe richness of the mixture may bevaried by adjustments of the needle valve 9 and the amount of the explosive mixture drawn into the engine may be regulated in the customary way, by adjustments of the throttle valve 5. To insure the desired initial supply of fluid fuel to start the engine, it is often desirable to temporarily close the choke valve 4 so that greater drawing or suction action will be produced in the tubular stem 3.

From a broad point of view, the so-called baille flanges 13 and 14 a'ord immovable obstructions which offer a constant resistance to the passage of air through the air intake conduit, in contradistinction to carbureters having spring pressed valves which move, and hence, vary the air conducting capacity with each impulse. In practice, l have found that highly improved results can be obtained by arranging permanent or immovable air obstructing flanges or baliles in the air intake conduit, as above described, and relying entirely on the throttle valve at the delivery end of the tube to vary the delivery capacity of the carbureted air, except in starting, when the choke valve is sometimes used.

When the carbureter is in normal action, the so-called choke valve performs no function whatever.7 To obtain the best results, the so-called baffles should be arranged to cause the air to take a zig-zag course through the tube and to make a downward sweep immediately over the fluid fuel intake port. As these batllesaford a contraction in the tube close to the fluid fuel intake port,

but on the air receiving side thereof, the indrawn air is caused to pass with high velocity at a point close to the fuel intake port and then is permitted to expand in the chamber which immediately overlies the said fuel intake port. ln this way, the suction required to pick up the fluid fuel isadorded and the air is caused to thoroughly commingle with the fuel or hydrocarbon vapor.

The above statements are based on actual use of the above described carbureter.

The carbureter described, as is obvious, is of very simple construction, vmay be made at small cost, has no parts that are likely to get out of order. Furthermore, it does not require fine adjustment of tuning up, as do carbureters having spring-pressed valves arranged to be opened and closed under vary,- ing impulses.

What l claim is:

1. `In a carburetor, a casing having an air passage in the form of a Venturi tube with a depressed bowl and fuel intake port opening into said bowl, said tube having its greatest contraction at one side of said bowl, and at a point between said fuel intake port and the air intake end of said tube, and the said tube at a point between said air intake and its point of greatest contraction, also having a permanently fixed .bame Hange.

Lalanne 2. ln a carbureter, a casing having an air passage in the form of a Venturi tube with a depressed bowl and a fuel intake port opening into said bowl, said tube having its greatest contraction at one side of said bowl and at a point between said fuel intake port and the air intake end of said tube, and the said tube, at a point between its air intake end and its point of greatest contraction.A having a permanentlv fixed baille flange that rises above said bowl.

3. In a carbureter, a casing having a tube for the intake of air, a fluid fuel intake port opening into the bottom of the intermediate portion of said tube, fix baille flanges in said tube between the intake end thereof and the said fuel port, the said bae flanges being arranged to aord a contraction in the said tube and to cause the air to take a zigzag downwardy course on its Way past the said fuel port, a throttle valve in the le-i' livery endof said tube, and a choke valve in the receiving end'of said tube adapted to be set in a position at one side of the passage through said tube, the said baiiles projecting, one upward and one downward.l and arranged to aordla contraction of the said tube and to cause the air to take a zigzag downward course on its way past said lfuel intake port.

4. ln a carbureter, the combination with a casing having an air intake conduitand a depending tubular stem communicating with the intermediate portion of said air delivery end of said air conduit, and a cup having-communication with the Said tubular stem for the supply of the fluid fuel thereto, i

and means for automatically maintaining an approximately constant level of fluid fuel in said cup.

ln testimony whereof'llax my signature in presencer of two witnesses.

ALBERT J. CNG. Witnesses I HARRY D. RE, F. D. MERCHANT.

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